The film follows Howard Ratner (Adam Sandler), a New York diamond store owner with a gambling addiction, a shaky marriage, and a cheating girlfriend (Julia Fox). Howard Ratner owes money to Arno (Eric Bogosian), and the thugs keep threatening to make him pay up. He thinks his bad luck will end when he buys a rare, uncut Ethiopian opal worth millions of dollars. The rough was originally intended to be auctioned, but things get complicated when Boston Celtics superstar Kevin Garnett walks into the gem store hoping to borrow the stone - it could bring him good luck in the NBA Finals.